drivers/net/usb/cx82310_eth.c - linux - Git at Google

 // SPDX-License-Identifier: GPL-2.0-or-later
 /*
  * Driver for USB ethernet port of Conexant CX82310-based ADSL routers
  * Copyright (C) 2010 by Ondrej Zary
  * some parts inspired by the cxacru driver
  */

 #include <linux/module.h>
 #include <linux/netdevice.h>
 #include <linux/etherdevice.h>
 #include <linux/ethtool.h>
 #include <linux/workqueue.h>
 #include <linux/mii.h>
 #include <linux/usb.h>
 #include <linux/usb/usbnet.h>

 enum cx82310_cmd {
 	CMD_START		= 0x84,	/* no effect? */
 	CMD_STOP		= 0x85,	/* no effect? */
 	CMD_GET_STATUS		= 0x90,	/* returns nothing? */
 	CMD_GET_MAC_ADDR	= 0x91,	/* read MAC address */
 	CMD_GET_LINK_STATUS	= 0x92,	/* not useful, link is always up */
 	CMD_ETHERNET_MODE	= 0x99,	/* unknown, needed during init */
 };

 enum cx82310_status {
 	STATUS_UNDEFINED,
 	STATUS_SUCCESS,
 	STATUS_ERROR,
 	STATUS_UNSUPPORTED,
 	STATUS_UNIMPLEMENTED,
 	STATUS_PARAMETER_ERROR,
 	STATUS_DBG_LOOPBACK,
 };

 #define CMD_PACKET_SIZE	64
 #define CMD_TIMEOUT	100
 #define CMD_REPLY_RETRY 5

 #define CX82310_MTU	1514
 #define CMD_EP		0x01

 /*
  * execute control command
  *  - optionally send some data (command parameters)
  *  - optionally wait for the reply
  *  - optionally read some data from the reply
  */
 static int cx82310_cmd(struct usbnet *dev, enum cx82310_cmd cmd, bool reply,
 		       u8 *wdata, int wlen, u8 *rdata, int rlen)
 {
 	int actual_len, retries, ret;
 	struct usb_device *udev = dev->udev;
 	u8 *buf = kzalloc(CMD_PACKET_SIZE, GFP_KERNEL);

 	if (!buf)
 		return -ENOMEM;

 	/* create command packet */
 	buf[0] = cmd;
 	if (wdata)
 		memcpy(buf + 4, wdata, min_t(int, wlen, CMD_PACKET_SIZE - 4));

 	/* send command packet */
 	ret = usb_bulk_msg(udev, usb_sndbulkpipe(udev, CMD_EP), buf,
 			   CMD_PACKET_SIZE, &actual_len, CMD_TIMEOUT);
 	if (ret < 0) {
 		if (cmd != CMD_GET_LINK_STATUS)
 			dev_err(&dev->udev->dev, "send command %#x: error %d\n",
 				cmd, ret);
 		goto end;
 	}

 	if (reply) {
 		/* wait for reply, retry if it's empty */
 		for (retries = 0; retries < CMD_REPLY_RETRY; retries++) {
 			ret = usb_bulk_msg(udev, usb_rcvbulkpipe(udev, CMD_EP),
 					   buf, CMD_PACKET_SIZE, &actual_len,
 					   CMD_TIMEOUT);
 			if (ret < 0) {
 				if (cmd != CMD_GET_LINK_STATUS)
 					dev_err(&dev->udev->dev,
 						"reply receive error %d\n",
 						ret);
 				goto end;
 			}
 			if (actual_len > 0)
 				break;
 		}
 		if (actual_len == 0) {
 			dev_err(&dev->udev->dev, "no reply to command %#x\n",
 				cmd);
 			ret = -EIO;
 			goto end;
 		}
 		if (buf[0] != cmd) {
 			dev_err(&dev->udev->dev,
 				"got reply to command %#x, expected: %#x\n",
 				buf[0], cmd);
 			ret = -EIO;
 			goto end;
 		}
 		if (buf[1] != STATUS_SUCCESS) {
 			dev_err(&dev->udev->dev, "command %#x failed: %#x\n",
 				cmd, buf[1]);
 			ret = -EIO;
 			goto end;
 		}
 		if (rdata)
 			memcpy(rdata, buf + 4,
 			       min_t(int, rlen, CMD_PACKET_SIZE - 4));
 	}
 end:
 	kfree(buf);
 	return ret;
 }

 #define partial_len	data[0]		/* length of partial packet data */
 #define partial_rem	data[1]		/* remaining (missing) data length */
 #define partial_data	data[2]		/* partial packet data */

 static int cx82310_bind(struct usbnet *dev, struct usb_interface *intf)
 {
 	int ret;
 	char buf[15];
 	struct usb_device *udev = dev->udev;
 	u8 link[3];
 	int timeout = 50;

 	/* avoid ADSL modems - continue only if iProduct is "USB NET CARD" */
 	if (usb_string(udev, udev->descriptor.iProduct, buf, sizeof(buf)) > 0
 	    && strcmp(buf, "USB NET CARD")) {
 		dev_info(&udev->dev, "ignoring: probably an ADSL modem\n");
 		return -ENODEV;
 	}

 	ret = usbnet_get_endpoints(dev, intf);
 	if (ret)
 		return ret;

 	/*
 	 * this must not include ethernet header as the device can send partial
 	 * packets with no header (and sometimes even empty URBs)
 	 */
 	dev->net->hard_header_len = 0;
 	/* we can send at most 1514 bytes of data (+ 2-byte header) per URB */
 	dev->hard_mtu = CX82310_MTU + 2;
 	/* we can receive URBs up to 4KB from the device */
 	dev->rx_urb_size = 4096;

 	dev->partial_data = (unsigned long) kmalloc(dev->hard_mtu, GFP_KERNEL);
 	if (!dev->partial_data)
 		return -ENOMEM;

 	/* wait for firmware to become ready (indicated by the link being up) */
 	while (--timeout) {
 		ret = cx82310_cmd(dev, CMD_GET_LINK_STATUS, true, NULL, 0,
 				  link, sizeof(link));
 		/* the command can time out during boot - it's not an error */
 		if (!ret && link[0] == 1 && link[2] == 1)
 			break;
 		msleep(500);
 	}
 	if (!timeout) {
 		dev_err(&udev->dev, "firmware not ready in time\n");
 		return -ETIMEDOUT;
 	}

 	/* enable ethernet mode (?) */
 	ret = cx82310_cmd(dev, CMD_ETHERNET_MODE, true, "\x01", 1, NULL, 0);
 	if (ret) {
 		dev_err(&udev->dev, "unable to enable ethernet mode: %d\n",
 			ret);
 		goto err;
 	}

 	/* get the MAC address */
 	ret = cx82310_cmd(dev, CMD_GET_MAC_ADDR, true, NULL, 0,
 			  dev->net->dev_addr, ETH_ALEN);
 	if (ret) {
 		dev_err(&udev->dev, "unable to read MAC address: %d\n", ret);
 		goto err;
 	}

 	/* start (does not seem to have any effect?) */
 	ret = cx82310_cmd(dev, CMD_START, false, NULL, 0, NULL, 0);
 	if (ret)
 		goto err;

 	return 0;
 err:
 	kfree((void *)dev->partial_data);
 	return ret;
 }

 static void cx82310_unbind(struct usbnet *dev, struct usb_interface *intf)
 {
 	kfree((void *)dev->partial_data);
 }

 /*
  * RX is NOT easy - we can receive multiple packets per skb, each having 2-byte
  * packet length at the beginning.
  * The last packet might be incomplete (when it crosses the 4KB URB size),
  * continuing in the next skb (without any headers).
  * If a packet has odd length, there is one extra byte at the end (before next
  * packet or at the end of the URB).
  */
 static int cx82310_rx_fixup(struct usbnet *dev, struct sk_buff *skb)
 {
 	int len;
 	struct sk_buff *skb2;

 	/*
 	 * If the last skb ended with an incomplete packet, this skb contains
 	 * end of that packet at the beginning.
 	 */
 	if (dev->partial_rem) {
 		len = dev->partial_len + dev->partial_rem;
 		skb2 = alloc_skb(len, GFP_ATOMIC);
 		if (!skb2)
 			return 0;
 		skb_put(skb2, len);
 		memcpy(skb2->data, (void *)dev->partial_data,
 		       dev->partial_len);
 		memcpy(skb2->data + dev->partial_len, skb->data,
 		       dev->partial_rem);
 		usbnet_skb_return(dev, skb2);
 		skb_pull(skb, (dev->partial_rem + 1) & ~1);
 		dev->partial_rem = 0;
 		if (skb->len < 2)
 			return 1;
 	}

 	/* a skb can contain multiple packets */
 	while (skb->len > 1) {
 		/* first two bytes are packet length */
 		len = skb->data[0] | (skb->data[1] << 8);
 		skb_pull(skb, 2);

 		/* if last packet in the skb, let usbnet to process it */
 		if (len == skb->len || len + 1 == skb->len) {
 			skb_trim(skb, len);
 			break;
 		}

 		if (len > CX82310_MTU) {
 			dev_err(&dev->udev->dev, "RX packet too long: %d B\n",
 				len);
 			return 0;
 		}

 		/* incomplete packet, save it for the next skb */
 		if (len > skb->len) {
 			dev->partial_len = skb->len;
 			dev->partial_rem = len - skb->len;
 			memcpy((void *)dev->partial_data, skb->data,
 			       dev->partial_len);
 			skb_pull(skb, skb->len);
 			break;
 		}

 		skb2 = alloc_skb(len, GFP_ATOMIC);
 		if (!skb2)
 			return 0;
 		skb_put(skb2, len);
 		memcpy(skb2->data, skb->data, len);
 		/* process the packet */
 		usbnet_skb_return(dev, skb2);

 		skb_pull(skb, (len + 1) & ~1);
 	}

 	/* let usbnet process the last packet */
 	return 1;
 }

 /* TX is easy, just add 2 bytes of length at the beginning */
 static struct sk_buff *cx82310_tx_fixup(struct usbnet *dev, struct sk_buff *skb,
 				       gfp_t flags)
 {
 	int len = skb->len;

 	if (skb_cow_head(skb, 2)) {
 		dev_kfree_skb_any(skb);
 		return NULL;
 	}
 	skb_push(skb, 2);

 	skb->data[0] = len;
 	skb->data[1] = len >> 8;

 	return skb;
 }


 static const struct driver_info	cx82310_info = {
 	.description	= "Conexant CX82310 USB ethernet",
 	.flags		= FLAG_ETHER,
 	.bind		= cx82310_bind,
 	.unbind		= cx82310_unbind,
 	.rx_fixup	= cx82310_rx_fixup,
 	.tx_fixup	= cx82310_tx_fixup,
 };

 #define USB_DEVICE_CLASS(vend, prod, cl, sc, pr) \
 	.match_flags = USB_DEVICE_ID_MATCH_DEVICE | \
 		       USB_DEVICE_ID_MATCH_DEV_INFO, \
 	.idVendor = (vend), \
 	.idProduct = (prod), \
 	.bDeviceClass = (cl), \
 	.bDeviceSubClass = (sc), \
 	.bDeviceProtocol = (pr)

 static const struct usb_device_id products[] = {
 	{
 		USB_DEVICE_CLASS(0x0572, 0xcb01, 0xff, 0, 0),
 		.driver_info = (unsigned long) &cx82310_info
 	},
 	{ },
 };
 MODULE_DEVICE_TABLE(usb, products);

 static struct usb_driver cx82310_driver = {
 	.name		= "cx82310_eth",
 	.id_table	= products,
 	.probe		= usbnet_probe,
 	.disconnect	= usbnet_disconnect,
 	.suspend	= usbnet_suspend,
 	.resume		= usbnet_resume,
 	.disable_hub_initiated_lpm = 1,
 };

 module_usb_driver(cx82310_driver);

 MODULE_AUTHOR("Ondrej Zary");
 MODULE_DESCRIPTION("Conexant CX82310-based ADSL router USB ethernet driver");
 MODULE_LICENSE("GPL");
	// SPDX-License-Identifier: GPL-2.0-or-later
	/*
	* Driver for USB ethernet port of Conexant CX82310-based ADSL routers
	* Copyright (C) 2010 by Ondrej Zary
	* some parts inspired by the cxacru driver
	*/

	#include <linux/module.h>
	#include <linux/netdevice.h>
	#include <linux/etherdevice.h>
	#include <linux/ethtool.h>
	#include <linux/workqueue.h>
	#include <linux/mii.h>
	#include <linux/usb.h>
	#include <linux/usb/usbnet.h>

	enum cx82310_cmd {
	CMD_START = 0x84, /* no effect? */
	CMD_STOP = 0x85, /* no effect? */
	CMD_GET_STATUS = 0x90, /* returns nothing? */
	CMD_GET_MAC_ADDR = 0x91, /* read MAC address */
	CMD_GET_LINK_STATUS = 0x92, /* not useful, link is always up */
	CMD_ETHERNET_MODE = 0x99, /* unknown, needed during init */
	};

	enum cx82310_status {
	STATUS_UNDEFINED,
	STATUS_SUCCESS,
	STATUS_ERROR,
	STATUS_UNSUPPORTED,
	STATUS_UNIMPLEMENTED,
	STATUS_PARAMETER_ERROR,
	STATUS_DBG_LOOPBACK,
	};

	#define CMD_PACKET_SIZE 64
	#define CMD_TIMEOUT 100
	#define CMD_REPLY_RETRY 5

	#define CX82310_MTU 1514
	#define CMD_EP 0x01

	/*
	* execute control command
	* - optionally send some data (command parameters)
	* - optionally wait for the reply
	* - optionally read some data from the reply
	*/
	static int cx82310_cmd(struct usbnet *dev, enum cx82310_cmd cmd, bool reply,
	u8 wdata, int wlen, u8 rdata, int rlen)
	{
	int actual_len, retries, ret;
	struct usb_device *udev = dev->udev;
	u8 *buf = kzalloc(CMD_PACKET_SIZE, GFP_KERNEL);

	if (!buf)
	return -ENOMEM;

	/* create command packet */
	buf[0] = cmd;
	if (wdata)
	memcpy(buf + 4, wdata, min_t(int, wlen, CMD_PACKET_SIZE - 4));

	/* send command packet */
	ret = usb_bulk_msg(udev, usb_sndbulkpipe(udev, CMD_EP), buf,
	CMD_PACKET_SIZE, &actual_len, CMD_TIMEOUT);
	if (ret < 0) {
	if (cmd != CMD_GET_LINK_STATUS)
	dev_err(&dev->udev->dev, "send command %#x: error %d\n",
	cmd, ret);
	goto end;
	}

	if (reply) {
	/* wait for reply, retry if it's empty */
	for (retries = 0; retries < CMD_REPLY_RETRY; retries++) {
	ret = usb_bulk_msg(udev, usb_rcvbulkpipe(udev, CMD_EP),
	buf, CMD_PACKET_SIZE, &actual_len,
	CMD_TIMEOUT);
	if (ret < 0) {
	if (cmd != CMD_GET_LINK_STATUS)
	dev_err(&dev->udev->dev,
	"reply receive error %d\n",
	ret);
	goto end;
	}
	if (actual_len > 0)
	break;
	}
	if (actual_len == 0) {
	dev_err(&dev->udev->dev, "no reply to command %#x\n",
	cmd);
	ret = -EIO;
	goto end;
	}
	if (buf[0] != cmd) {
	dev_err(&dev->udev->dev,
	"got reply to command %#x, expected: %#x\n",
	buf[0], cmd);
	ret = -EIO;
	goto end;
	}
	if (buf[1] != STATUS_SUCCESS) {
	dev_err(&dev->udev->dev, "command %#x failed: %#x\n",
	cmd, buf[1]);
	ret = -EIO;
	goto end;
	}
	if (rdata)
	memcpy(rdata, buf + 4,
	min_t(int, rlen, CMD_PACKET_SIZE - 4));
	}
	end:
	kfree(buf);
	return ret;
	}

	#define partial_len data[0] /* length of partial packet data */
	#define partial_rem data[1] /* remaining (missing) data length */
	#define partial_data data[2] /* partial packet data */

	static int cx82310_bind(struct usbnet dev, struct usb_interface intf)
	{
	int ret;
	char buf[15];
	struct usb_device *udev = dev->udev;
	u8 link[3];
	int timeout = 50;

	/* avoid ADSL modems - continue only if iProduct is "USB NET CARD" */
	if (usb_string(udev, udev->descriptor.iProduct, buf, sizeof(buf)) > 0
	&& strcmp(buf, "USB NET CARD")) {
	dev_info(&udev->dev, "ignoring: probably an ADSL modem\n");
	return -ENODEV;
	}

	ret = usbnet_get_endpoints(dev, intf);
	if (ret)
	return ret;

	/*
	* this must not include ethernet header as the device can send partial
	* packets with no header (and sometimes even empty URBs)
	*/
	dev->net->hard_header_len = 0;
	/* we can send at most 1514 bytes of data (+ 2-byte header) per URB */
	dev->hard_mtu = CX82310_MTU + 2;
	/* we can receive URBs up to 4KB from the device */
	dev->rx_urb_size = 4096;

	dev->partial_data = (unsigned long) kmalloc(dev->hard_mtu, GFP_KERNEL);
	if (!dev->partial_data)
	return -ENOMEM;

	/* wait for firmware to become ready (indicated by the link being up) */
	while (--timeout) {
	ret = cx82310_cmd(dev, CMD_GET_LINK_STATUS, true, NULL, 0,
	link, sizeof(link));
	/* the command can time out during boot - it's not an error */
	if (!ret && link[0] == 1 && link[2] == 1)
	break;
	msleep(500);
	}
	if (!timeout) {
	dev_err(&udev->dev, "firmware not ready in time\n");
	return -ETIMEDOUT;
	}

	/* enable ethernet mode (?) */
	ret = cx82310_cmd(dev, CMD_ETHERNET_MODE, true, "\x01", 1, NULL, 0);
	if (ret) {
	dev_err(&udev->dev, "unable to enable ethernet mode: %d\n",
	ret);
	goto err;
	}

	/* get the MAC address */
	ret = cx82310_cmd(dev, CMD_GET_MAC_ADDR, true, NULL, 0,
	dev->net->dev_addr, ETH_ALEN);
	if (ret) {
	dev_err(&udev->dev, "unable to read MAC address: %d\n", ret);
	goto err;
	}

	/* start (does not seem to have any effect?) */
	ret = cx82310_cmd(dev, CMD_START, false, NULL, 0, NULL, 0);
	if (ret)
	goto err;

	return 0;
	err:
	kfree((void *)dev->partial_data);
	return ret;
	}

	static void cx82310_unbind(struct usbnet dev, struct usb_interface intf)
	{
	kfree((void *)dev->partial_data);
	}

	/*
	* RX is NOT easy - we can receive multiple packets per skb, each having 2-byte
	* packet length at the beginning.
	* The last packet might be incomplete (when it crosses the 4KB URB size),
	* continuing in the next skb (without any headers).
	* If a packet has odd length, there is one extra byte at the end (before next
	* packet or at the end of the URB).
	*/
	static int cx82310_rx_fixup(struct usbnet dev, struct sk_buff skb)
	{
	int len;
	struct sk_buff *skb2;

	/*
	* If the last skb ended with an incomplete packet, this skb contains
	* end of that packet at the beginning.
	*/
	if (dev->partial_rem) {
	len = dev->partial_len + dev->partial_rem;
	skb2 = alloc_skb(len, GFP_ATOMIC);
	if (!skb2)
	return 0;
	skb_put(skb2, len);
	memcpy(skb2->data, (void *)dev->partial_data,
	dev->partial_len);
	memcpy(skb2->data + dev->partial_len, skb->data,
	dev->partial_rem);
	usbnet_skb_return(dev, skb2);
	skb_pull(skb, (dev->partial_rem + 1) & ~1);
	dev->partial_rem = 0;
	if (skb->len < 2)
	return 1;
	}

	/* a skb can contain multiple packets */
	while (skb->len > 1) {
	/* first two bytes are packet length */
	len = skb->data[0] \| (skb->data[1] << 8);
	skb_pull(skb, 2);

	/* if last packet in the skb, let usbnet to process it */
	if (len == skb->len \|\| len + 1 == skb->len) {
	skb_trim(skb, len);
	break;
	}

	if (len > CX82310_MTU) {
	dev_err(&dev->udev->dev, "RX packet too long: %d B\n",
	len);
	return 0;
	}

	/* incomplete packet, save it for the next skb */
	if (len > skb->len) {
	dev->partial_len = skb->len;
	dev->partial_rem = len - skb->len;
	memcpy((void *)dev->partial_data, skb->data,
	dev->partial_len);
	skb_pull(skb, skb->len);
	break;
	}

	skb2 = alloc_skb(len, GFP_ATOMIC);
	if (!skb2)
	return 0;
	skb_put(skb2, len);
	memcpy(skb2->data, skb->data, len);
	/* process the packet */
	usbnet_skb_return(dev, skb2);

	skb_pull(skb, (len + 1) & ~1);
	}

	/* let usbnet process the last packet */
	return 1;
	}

	/* TX is easy, just add 2 bytes of length at the beginning */
	static struct sk_buff cx82310_tx_fixup(struct usbnet dev, struct sk_buff *skb,
	gfp_t flags)
	{
	int len = skb->len;

	if (skb_cow_head(skb, 2)) {
	dev_kfree_skb_any(skb);
	return NULL;
	}
	skb_push(skb, 2);

	skb->data[0] = len;
	skb->data[1] = len >> 8;

	return skb;
	}


	static const struct driver_info cx82310_info = {
	.description = "Conexant CX82310 USB ethernet",
	.flags = FLAG_ETHER,
	.bind = cx82310_bind,
	.unbind = cx82310_unbind,
	.rx_fixup = cx82310_rx_fixup,
	.tx_fixup = cx82310_tx_fixup,
	};

	#define USB_DEVICE_CLASS(vend, prod, cl, sc, pr) \
	.match_flags = USB_DEVICE_ID_MATCH_DEVICE \| \
	USB_DEVICE_ID_MATCH_DEV_INFO, \
	.idVendor = (vend), \
	.idProduct = (prod), \
	.bDeviceClass = (cl), \
	.bDeviceSubClass = (sc), \
	.bDeviceProtocol = (pr)

	static const struct usb_device_id products[] = {
	{
	USB_DEVICE_CLASS(0x0572, 0xcb01, 0xff, 0, 0),
	.driver_info = (unsigned long) &cx82310_info
	},
	{ },
	};
	MODULE_DEVICE_TABLE(usb, products);

	static struct usb_driver cx82310_driver = {
	.name = "cx82310_eth",
	.id_table = products,
	.probe = usbnet_probe,
	.disconnect = usbnet_disconnect,
	.suspend = usbnet_suspend,
	.resume = usbnet_resume,
	.disable_hub_initiated_lpm = 1,
	};

	module_usb_driver(cx82310_driver);

	MODULE_AUTHOR("Ondrej Zary");
	MODULE_DESCRIPTION("Conexant CX82310-based ADSL router USB ethernet driver");
	MODULE_LICENSE("GPL");